JPS6410001B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD This invention relates to an emulsifier for emulsion polymerization, a method for preparing the emulsifier, and a latex formulation containing the emulsifier. In particular, the emulsifier of this invention has the general formula A half vinyl ester of C21 dicarboxylic acid represented by the formula, where x and y are integers from 3 to 9, the sum of x and y is 12, one z is COOH and the other z is hydrogen. . Prior Art Emulsion polymerization is one of the load polymerization methods. In this emulsion polymerization, the monomer is a medium (usually water)
emulsified within. For this emulsification, an emulsifier or a micelle-forming substance such as soap, alkyl sulfonate, etc. is used. Furthermore, this method requires an initiator in addition to the monomers, water (as the continuous phase) and emulsifier. Hydrogen peroxide, ammonium peroxysulfate, etc. are used as this initiator. The main advantage of emulsion polymerization is that high molecular weight polymers can be obtained at very high polymerization rates. In this respect, emulsion polymerization is incomparable with other free radical polymerization methods. Therefore, this method is widely used. The emulsifier for emulsion polymerization disclosed in Meis and Werk, U.S. Pat. It is a mixture with a water-soluble salt of an unsaturated carboxylic acid (especially an alkali metal salt). Force, one of the co-applicants of this patent application, in U.S. Pat. No. 4,259,459,
Acid-catalyzed formaldehyde-treated mixtures of tall oil fatty acids and resin acids are disclosed as emulsifiers for emulsion polymerization. In addition, Blackley wrote, ``The theory and practice of emulsion polymerization.''
Polymerization Theory and Practice)
(1975), Chapter 7 discusses the use of rosin acid and fatty acid compounds as micelle-forming substances. However, what is of concern is the effect that impurities in fatty acid or rosin acid mixtures (particularly those derived from unsaturated fatty acids) have on polymerization. Wilson et al.
Engineering Chemistry
"Engineering Chemistry" (1948), Volume 40, No.
On page 530, it is reported that soaps derived from linoleic acid or linolenic acid retard the copolymerization of styrene and butadiene. Of course, the emulsifier must not alter the physical properties of the polymer. A major concern of polymer manufacturers and users is emulsifier migration within the polymer. This migration may be a mere visual or aesthetic problem, but when the polymer is used as a hose for fuel such as gasoline, the effects of migration may be significant. There are two methods to suppress the problem of emulsifier migration. The first method is to wash the emulsifier from the latex before starting the polymerization, and the second method is to polymerize the emulsifier into the polymer and permanently incorporate the emulsifier into the polymer. The first method is usually used, but this increases the number of steps and therefore increases the cost. The second method is not often used because such emulsifiers are very expensive and their low polymerization activity limits their range of use. Greene et al., Journal of Colloid and Interface Science.
Science), vol. 32, p. 90 (1970), ``In Situ Polymerization of Surfactants on Latex Particles''.
Surface−Active Agent on Latex Particles)”
In , 9 was used as a micelle former to produce a 60/40 styrene-butadiene copolymer.
(and 10)-acrylamide stearic acid (9-
acrylamidostearicacid). This article states that in-situ polymerized soap has better mechanical stability than separately added monomer soap if its surface coverage is 20% or more. OBJECTS OF THE INVENTION It is an object of the invention to provide new latex formulations which, when polymerized by emulsion polymerization, do not induce migration of the emulsifier for the polymerization. Another object of the invention is to provide an emulsifier for emulsion polymerization, which can be permanently incorporated into the polymer by polymerization. Another object of this invention is to have no polymerization inhibitory effect;
Another object of the present invention is to provide an emulsifier that does not have a negative effect on the physical properties of the produced polymer. Yet another object of this invention is to provide an emulsifier that is less expensive than conventional polymerization emulsifiers. SUMMARY OF THE INVENTION The above object is achieved by the discovery of emulsifiers that can be incorporated into polymers. The emulsifier for this emulsion polymerization has the general formula It is a half vinyl ester of C21 dicarboxylic acid represented by In addition, in the formula, x and y are 3 to 9
is an integer, the sum of x and y is 12, one z is COOH and the other z is hydrogen. Preferred emulsifiers have the general formula It is a half vinyl ester of C21 dicarboxylic acid represented by This emulsifier is then used in a mixture with a mixture of disproportionated fatty acids and/or C21 dicarboxylic acids. Description of the Examples The essence of the invention is 5-carboxy-4-hexyl-2cyclohexene-1-octanoic acid (5-
carb oxy−4−hexy1−2 cyclohexene−1−
C21-cycloaliphatic dicarboxylic acids, such as octanoic acid
The isomer mixture formed when a mixture of polyvinyl acids and vinyl acetates is reacted with vinyl acetate can be used as an effective emulsifier for emulsion polymerization. These isomers have the general formula It is indicated by. In the formula, x and y are integers of 3 to 9, the sum of x and y is 12, one z is a carboxyl group (-COOH), and the other z is hydrogen. The isomer with x=5 and y=7 is a superior composition, but differs in the position of the cyclohexene ring relative to the carbon chain.
Half vinyl ester of C21 dicarboxylic acid (half
vinyl ester) is present in small amounts. In this specification, the composition represented by the above general formula is referred to as "C21
``half vinyl ester of dicarboxylic acid'' or ``diacid half vinyl ester''
I will call it "ester". The C21 dicarboxylic acid used in this invention is produced from linoleic acid contained in various animal oils, vegetable oils, and tall oil. This C21 dicarboxylic acid is obtained by reacting linoleic acid with acrylic acid and iodine as a catalyst. One method for producing the C21 dicarboxylic acids used in the ester production of this invention is disclosed in the U.S. patent entitled "Selective Reaction of Fatty Acids and Their Separation."
Disclosed in No. 3753968. A method for synthesizing vinyl diacid esters is disclosed in "Organic Synthesis" 1963, Vol. 4, p. 977. This method involves combining C21 dicarboxylic acid with vinyl acetate in the presence of mercuric acetate. In this method, a high esterification rate is obtained due to the interaction of mercuric acetate. The reaction formula for the continuous reaction of isomers of diacid is shown below. Vinyl esters of C21 dicarboxylic acids can also be obtained by reaction with acetylene, but this reaction is not suitable for small-scale laboratory equipment. The emulsion polymerization emulsifier of this invention is detailed in the following examples. Example 1 103 g (1.2 mol) of vinyl acetate and 71.2 g (0.2
mol) of C21 dicarboxylic acid in the presence of nitrogen. The reaction is carried out in a 250 ml round bottom three-necked flask connected to a reflux condenser, thermometer and gas supply. The diacid compound is dissolved by warm shaking. Next, 0.8 g of mercuric acetate was added and the reaction mixture was stirred with a magnetic stirrer for 30 min.
Stir for a minute. Add two drops of 100% sulfuric acid to the mixture. (100% sulfuric acid is prepared by mixing 10 ml of 95% H ₂ SO ₄ and 7.3 ml of 20% oleum.) The reaction is carried out under heat and stirring.
Heating is discontinued after 3 hours and stirring is continued overnight. Next, 0.56 g of sodium acetate is added to neutralize the sulfuric acid and unreacted vinyl acetate is removed under vacuum. The reaction product is then diluted with 100 ml of cyclohexene and washed twice with 25 ml of saturated sodium chloride solution. Finally, the product is dried over anhydrous sodium sulfate and the solvent is stripped off under vacuum. Analysis of the product was performed by thin layer chromatography. Silica gel (9/1, CHCl ₃ /methanol) separation or C18 reversed phase plate (9/1,
The separation (acetonitrile/water) was good, and the results of reaction progress evaluation were clear. The chromatogram obtained confirmed the presence of a half vinyl ester of C21 dicarboxylic acid. Example 2 Polymerization rate of ester obtained using the emulsifier of the present invention, polymer particle size and particle size distribution, and polymerization rate of ester obtained using a general emulsifier,
To compare the particle size and particle size distribution of the polymers, the reaction product in Example 1 and a mixture of this reaction product and a fatty acid emulsifier (a disproportionated mixture of tall oil fatty acids) were used to prepare styrene. −
Butadiene polymerization was carried out. Common emulsifiers designated as plant mixes are mixed rosin acids and partially hydrogenated animal fatty acid emulsifiers. A comparison was also made between the effect of the emulsifier of this invention and that of untreated C21 dicarboxylic acid. Table 1 shows the polymerization results using these emulsifiers.

[Table] As shown in Table 1, polymerization occurs with this ester, but the polymerization rate is slightly lower than when other emulsifiers are used. The particle size distribution, which is an index of particle size and molecular weight distribution, is not much different from that when using Plantomics or dicarboxylic acid. However, when using a mixture of diacid half vinyl ester and disproportionated tall oil fatty acids,
The polymerization rate is improved compared to when the ester is used alone, and the particle properties are improved accordingly. Furthermore, the completely polymerized latex of the sample was dissolved in an appropriate solvent, and the molecular weight distribution was measured using thin layer chromatography. The method involves a gradient elution in a mobile phase that becomes progressively richer in chloroform. As a result of the measurement, a decrease in low molecular weight polymers was observed. Also, no new molecular weight species were measured for the samples using plantomics. Example 3 A polymerization reaction was also carried out in a butadiene-acrylonitrile system. The results were similar to those in the above examples, but the differences between the samples were smaller. The results are shown in Table 2.

【table】

[Table] Tell

Claims (1)

[Scope of Claims] 1. An emulsion polymerization method comprising combining a monomer, an emulsifier, an initiator and water as a continuous phase, wherein the emulsifier has the general formula It is a half vinyl ester of a C21 dicarboxylic acid represented by emulsion polymerization method. 2. The emulsion polymerization method according to claim 1, wherein the monomer is a mixture of styrene and butadiene. 3. The emulsion polymerization method according to claim 1, wherein the monomer is a mixture of acrylonitrile and butadiene. 4. The emulsion polymerization method according to claim 1, wherein x is 5 and y is 7. 5. The emulsion polymerization method according to claim 1, wherein the emulsifier contains a compound selected from the group consisting of disproportionated fatty acids and C21 dicarboxylic acids. 6. The emulsion polymerization method according to claim 5, wherein the disproportionated fatty acid is derived from tall oil. 7 An emulsifier used in an emulsion polymerization process comprising combining a monomer, an emulsifier, an initiator and water as a continuous phase, which has the general formula , where x and y are integers of 3 to 9,
An emulsifier characterized in that the sum of x and y is 12, one z is COOH and the other z is hydrogen. 8. The emulsifier according to claim 7, wherein x is 5 and y is 7.